1. Field of the Invention
The present invention relates to a switch-based (storage) virtualization technique in a storage area network (SAN), and to a management method for a name, which is given to a port of a switch providing a virtualized storage.
2. Description of the Prior Art
In a Fibre Channel (FC)-SAN environment, or an IP-SAN environment (i.e. using the internet Small Computer System Interface (iSCSI) obtained by encapsulating the Small Computer System Interface (SCSI) in the Transmission Control Protocol/Internet Protocol (TCP/IP)), an apparatus such as a server or a storage device is treated as a node. To identify a node in the SAN (or in the FC-SAN), each node has associated therewith 24-bit address information called a port ID and 64-bit name information called a World Wide Name (WWN). In addition, in IP-SAN, each node has an IP address (32-bit address information in Ipv4 or 128-bit address information in Ipv6), along with 48-bit address information called a Media Access Control (MAC) address, and 255-byte name information called an iSCSI.
The name information cannot be changed because it is generated based upon information permanently allocated to hardware of a node. Programs of a Simple Name Server (SNS) in the FC-SAN, an internet Storage Name Server (iSNS) in the IP-SAN, and the like are executed, whereby a relationship between the name information and the address information, or the like is managed, and the information is provided. After acquiring or setting the address information, the node connected to the SAN registers the name information and the address information of its own in a table held by an apparatus having these programs (e.g., see Tom Clark “SAN, Implementation of Practical Fibre Channel Storage Area Network”, Piason Education, Dec. 25, 2000, p. 40-42, and 76-83, or Mike Frase, “Troubleshooting Storage Networks”, [online], [retrieved on Jan. 10, 2003], available on the Cisco Web site.
In a switch providing a storage virtualization mechanism in the SAN environment, a volume or a logical unit (LU) of a virtualized storage is provided (e.g., see Mogi Ryuta, “Realize Functional Reinforcement and Package Management of a SAN through Virtualization of a Storage”, Nikkei Windows Pro, August 2002 (No. 65), p. 13-15). In the following description, a port providing a volume or an LU of a virtualized storage is referred to as a virtual port.